Hi,
Thank you for developing the great feature. I tested this feature and checked the documentation. Currently, the
documentationfor the pg_stat_prefetch_recovery view is included in the description for the pg_stat_subscription view.
https://www.postgresql.org/docs/devel/monitoring-stats.html#MONITORING-PG-STAT-SUBSCRIPTION
It is also not displayed in the list of "28.2. The Statistics Collector".
https://www.postgresql.org/docs/devel/monitoring.html
The attached patch modifies the pg_stat_prefetch_recovery view to appear as a separate view.
Regards,
Noriyoshi Shinoda
-----Original Message-----
From: Thomas Munro <thomas.munro@gmail.com>
Sent: Friday, April 8, 2022 10:47 AM
To: Justin Pryzby <pryzby@telsasoft.com>
Cc: Tomas Vondra <tomas.vondra@enterprisedb.com>; Stephen Frost <sfrost@snowman.net>; Andres Freund
<andres@anarazel.de>;Jakub Wartak <Jakub.Wartak@tomtom.com>; Alvaro Herrera <alvherre@2ndquadrant.com>; Tomas Vondra
<tomas.vondra@2ndquadrant.com>;Dmitry Dolgov <9erthalion6@gmail.com>; David Steele <david@pgmasters.net>; pgsql-hackers
<pgsql-hackers@postgresql.org>
Subject: Re: WIP: WAL prefetch (another approach)
On Fri, Apr 8, 2022 at 12:55 AM Justin Pryzby <pryzby@telsasoft.com> wrote:
> The docs seem to be wrong about the default.
>
> + are not yet in the buffer pool, during recovery. Valid values are
> + <literal>off</literal> (the default), <literal>on</literal> and
> + <literal>try</literal>. The setting <literal>try</literal>
> + enables
Fixed.
> + concurrency and distance, respectively. By default, it is set to
> + <literal>try</literal>, which enabled the feature on systems where
> + <function>posix_fadvise</function> is available.
>
> Should say "which enables".
Fixed.
> Curiously, I reported a similar issue last year.
Sorry. I guess both times we only agreed on what the default should be in the final review round before commit, and I
letthe docs get out of sync (well, the default is mentioned in two places and I apparently ended my search too soon,
changingonly one). I also found another recently obsoleted sentence: the one about showing nulls sometimes was no
longertrue. Removed.
